CD281, or Toll-like receptor 1, is a human gene encoded by TLR1. It may also be known as: TIL; CD antigen CD281; Toll/interleukin-1 receptor-like protein; TIL. LPRS5; rsc786. The encoded protein has an amino acid length of 786 and a mass of 90.3 kDa. CD281 is a member of the Toll-like receptor family. Homologs of this gene exist in other organisms, including: Mouse, Fly, Rat, Zebrafish, Frog.